The major theme of the PPG is the use of induced mutant mouse models to identify new genes and pathways involved in atherosclerosis. As a consequence, all of the projects in the PPG have as major endpoints the assessment of atherosclerotic lesions. Core 'A'will assist investigators in making 3 types of measurements including: 1) quantitation of cross sectional lesion area in the aortic root and brachiocephalic artery (BCA), 2) quantitation of aortic surface lesion area by the en face method, and 3) qualitative and quantitative assessment of plaque progression phenotypes. The first two of these and some measurements pertaining to the third will be done in Dr. Breslow's laboratory at Rockefeller. Measurements of plaque progression phenotypes will also be done in Dr. Tabas'laboratory at Columbia. In addition, all PPG projects have proposed using Laser Capture Microdissection (LCM) to assess gene expression in various cell types in atherosclerotic lesions. Core 'A'will act as intermediary with Dr. Edward Fisher's Laboratory at New York University Medical Center to train PPG investigators/technicians in the use of the LCM technique. A trained person will then be allowed to use the machinery on a sign up basis. Dr. Fisher will consult/collaborate on each of these projects.